Carotenoids in the adult
diet enhance egg and juvenile production in the sea urchin Lytechinus
variegatus
S.B. George, J.M. Lawrence, A.L. Lawrence, J. Smiley,
L. Plank-2001
Aquaculture, 199(3-4): 35-369
Abstract:
This study provides clear evidence of the important
role of xanthophylls (lutein and zeaxanthin) over the hydrocarbon carotene (β-carotene)
for reproduction of the sea urchin Lytechinus variegatus. Although
carotenoids are found extensively in sea urchin eggs, limited knowledge is
available on the effect of carotenoids, in the diet of adults, on the
quality of the gametes produced. The present study investigated the effect
of vitamins alone, vitamins and beta-carotene, and vitamins and a carotenoid
mixture consisting of 60% trans-zeaxanthin, 25% trans-lutein
and 15% other xanthophylls in a semi-purified diet of the adult sea urchins.
Diet had a greater effect on the number of eggs spawned than on egg size.
The largest numbers of eggs were produced by females fed the β-carotene
diet (~500000/female) and those fed xanthophylls (~2.6 million/female).
Females fed vitamins alone spawned less than 400000 eggs. Larvae from
parents fed xanthophylls were larger throughout development, developed
faster, had higher survival rates and attained metamorphic competence faster
than those from the other two treatments. The numbers of juveniles
originating from parents fed xanthophylls were significantly higher
(>500/female) than those from parents fed β-carotene (15/female). No
juveniles were produced by parents fed vitamins alone. This is important for
sea urchin aquaculture, as a semi-purified diet containing xanthophylls
would enable production of large numbers of juveniles with high survival
rates. The data indicate that a defined semi-purified diet that will support
normal sea urchin reproduction and development is available. Thus, the sea
urchin model can be used to evaluate nutritional requirements for
reproduction and development and the effects of potential toxic substances.
(Department of Biology, Georgia Southern University,
PO Box 8042, Statesboro, GA 30460, USA, e-mail: georges@gsaix2.cc.gasou.edu)